... mMdithiothreitol, as previouslydescribed [11]. For the determination of kinetic p arameters(Kmand kcat) the concentration of t he labelled substratesranged from 0.02 to 4 mM. A curve of dependence ... measured as described in the Experimental procedures. The results reported are the average of at least threeindependent assays. IMP, inosine monophosphate; nd, not detectable; ND, not determined; ... particularlyimportant. In fact, these investigations will be fundamentalfor the design of nucleoside derivatives that could interferewith enzyme function and stability, thus playing a role both in the therapy of...